For short reach optical networks (e.g., a data center, a centralized radio access network (C-RAN), a wave-division multiplexing passive optical network (WDM-PON), etc.) remote modulation with carrier distribution is a promising technology. Using such technology, costs may be reduced by sharing centralized light sources.
An external modulator (e.g., silicon (Si) modulator) suitable for remote modulation may be packaged in non-hermetic form and operated in a high temperature environment without the need for a thermoelectric cooler (TEC). However, the external modulator has some practical drawbacks. For example, an external modulator such as silicon Mach-Zehnder modulators (MZM) is dependent on the polarization orientation of the incoming optical carrier.